Grandiose narcissism and prosociality are important topics in personality and social psychology, but research on their interplay is lacking. We present a first large-scale, systematic, and multimethod investigation linking the two. In 2 studies (N1 = 688, N2 = 336), we assessed grandiose narcissism comprehensively (i.e., agentic and communal narcissism) and examined its relations with instantiations of prosociality, namely, objective prosociality (actual behavior in Study 1; round-robin informant-reports in a real-life setting in Study 2) and subjective prosociality (self-perceptions in Studies 1 and 2). We obtained a consistent set of results. Agentic narcissism was related to lower objective prosociality and lower subjective prosociality. Communal narcissism, by contrast, was unrelated to objective prosociality, but was related to higher subjective prosociality. Additionally, we tested for prosociality self-enhancement among agentic and communal narcissists. Agentic narcissists evinced the same (and modest) level of prosociality self-enhancement as their non-narcissistic counterparts. Communal narcissists, by contrast, evinced substantial levels of prosociality self-enhancement, whereas their non-narcissistic counterparts did not enhance their prosociality at all. We discuss implications of the findings for the literature on narcissism and antisociality, and for the concept of prosocial personality.